Impulse-controlled timer for energizing devices for preselected periods



Sept. 27, 1949.

E NELSON DEVICES FOR PRESELECTED PERIODS Filed Dec. 20, 1946 N /2 WT? A?7. I?

INVENTOR. E. NELSON BY a;

ATTORNEY Patented Sept. 27 1949 ERAHEENT Etch RIMIZEULSE: QONTRQLLED,:TIMER.:EQR \ENER" IGIZING DEVICES, FOR .BRESELEQTEDI'PE- Melvin hNiclsonrllurhankacaclifl, assignon-to :Mel M. Burns Application December20, 194,6,Serial No."717;454

' This :invention relates tottiming devices trtor -measuring time, andparticularlyito. :devicesathat measure time in terms of a predetermined:unit or: alrnuitiple thereof. I It has particular utility in "connectionwith coincontrolled mechanisms for a,

energy of a springs-is. usezdutogshiftian; actuatin element-i inresponseitOi-a vcontrolimg pulse; i .(2) the actuating element .isreturnedatoiits initial position. at war constant :.speed .byoa :.clockmotor; and 1' (13). ;.the. spring isxautomatioally:rewoundiby the;return .ofzthe. actuating zelement.

5 Gthermore specifioobjectszandieaturesmfitheinventionwviilabecomeiapparent from thmdescril tionztorfollow.

Essentially, :-the invention:comprisesi-aiswitch- -actuating.- elementmovable: inzone: directionezhysa spring mechanism linden-the control,ofiarrescapement response .to 5,00DtliO1liIlE iimpnlses, with atimingmotoizior; restoring the; sw-it cheactuating :elementto. its initial{posit-i011-v atia constantspeed, in :wmchathe restoring a movement ofcthe omotor also reloadsathe springrso :sthat thellatter is: a wayswfiective to .;act in :response to ,-a received impulse.

. the drawing 1mg. ii is aifrontaelevationa-viewofmnesemhddi- 'ment oiltheiinvention.

T EigLZ isia detail vertical section taken-aalongzthe ii-nefII -ILOf'Fig; 1 hand i Eight -is a circuit diagram-of: thQEBIGCtIiOZh-SYS-,temuofithe mechanism.

. iReferringfirstitotFig. 11, .the apparatus there shown comprises adifferential mechanism.:con- :sisti-n'gof a pair of worms l-flsan'd;l-.'l':-respectively,

both on which. mesh: witha common mor-mwheel t2.Asnis-clearlyapparent;frorrrthedrawingzthe worms lznaan'di-l .l; are;parallel toteachsotheraand aengagetheworm wheeli'hatrdiametrieazllyzopposite :points. 'Enrthermore'. the worm :wheel;this supported 5 for "free rotation =-on ea .etuh .wshaft t3whicmisslidablylmountedi tor free verticah movement.;;Thus:refierring.toafig;2,2the-shafts thex- :tends throughaai slot'fliin a. frame: plate I St on xwhichi-the rmechanismi is:mounte;d..;'Ihe.-shaf-t;is

:2 $6 which is "positioned between-theworm 1 wheel it-and the front faceof theplate 1 l-5,- and anti: 11 which threaded onto the rear end of'the :shaft h'i and which slides along the rear face'of the -plate t5.'aT-he worm wheel [2 -may be rewtaine'd on' the shaft: t3-against= thewasher H; by

a washer wand a .-s=plit retaining ring 1 I i-which mounted inan'annular groove provided-there- :foron the shaft t3.

The worms I 0 and t l may-be convenientlysu-pported inbearings-constitutedbyears 20 extendoing 'forwardly 'from 'the :baseplate tiand having aperturesthereirr through whichreduced-:end'portionsfllofrtheworms: hand: I k-project.

In operation,.=theaworm wheel I2 andz its supporting shaft: 113* are:moved: downwardly by. rota- :tion ofthe worm? I I, and upwardly byrotation of the worm: t0. The arrangementiszsuch thatthe worm: l-I;moves throughqone complete revolution at attime; causing the-twormzwheelttto he; moved down a predetermined distance. Wheneverthe :worm wheel:I2 is movedout of its uppermostposition the worm I0 is actuated indirection to reosto-rerthe wonmwvheelzto.itsmppermosh position.

fMovement of thetworm; I Lisproduced by;a:l1el- --ical :spring 5 whichis 1 connected :to :the; lower reduced-section '22 otthe worm and isconstantly loaded to apply torque to the worm. 5Movement of thezworminresponse to: the torque .isproduced whenever.aanrescapement mechanism.is" actuated, :this escapement mechanism normally restraining thezwormlilffromsrotation.

1 shown in the drawing, :the escapement "mechanism comprises a. .pin'"26extending; radially "from the extensioniniat' the upper: end of worm aIl,vwhich=pin;isinormally engaged-by an armiz'l on :a I lever 28 which:is fulcrumed at 29 "to: the frame plate l5. The-lever 28 is normallyretained inthe positions showngin .which the. arm 21. engages the pin26, by a tension spring 30 which is -stretchedz;between' t-heslower endof the lever 28 and the frameplatefi. :Atiitsupper end, the lever=28carries a pole. piece'3 I which-is associated twithnanactuatingtmagnetrfi.

Whenever: the. magnet 32. is energized,',the. pole 1 piece'r3lr' isattracted thereby: to rock: the lever .28 counter-clockwise anddisengage the'armi2'l from :the pin :26, awhereupon tthe worm 1! lrotated through half a revolution -.bythe-spring:25; At

:the end. of this half revolution the worm is'stoppedsbyiengagementof'the .pin;26 with .aisec- -ond: arm; 33 :on thelever 28. 1 However, .when the magnet-1322b :deenergized;;the;leveranyis restored .to:normal :position by the spring bviearsupp rtedasain t iiting mw m an -wa h r 555 rrvinarlthearmsurontloir ens'sementawithlthezpin 26 and permitting the worm H to move throughanother half revolution when it is again stopped by engagement of thepin 26 against the arm 21.

It will be observed that the escapement mechanism described functions topermit one complete revolution of the worm H by the spring 25 inresponse to each energizing impulse applied to the magnet 32,independent of the length of the impulse.

When the worm wheel I2 is in its uppermost position, the front end ofthe shaft l3 bears against a plunger 35 of a switch36, which switchcontains contacts that are opened when the plunger 35 is depressed andare closed when the plunger is released. Referring to Fig. 3, it will.

be observed that contacts 36a of this switch 36 are connected in serieswith a power line 31 and a motor 38, so that the motor 38 runs wheneverconnected into the electrical circuit of a device to be controlled.

It will be observed that a plurality of impulses can be successivelyapplied to the magnet 32 and that each impulse will cause the worm wheelI2 the switch contacts 360. are closed. As shown in Fig. 3 the circuitfor supplying impulses to the magnet 32 may also include this same powerline 3"! in conjunction with a switch 44. One field of use for thepresent invention is in coincontrolled mechanisms, and, in Fig. 1, theswitch 44 is shown as having an actuating arm 39 which is rocked toactuatethe switch 44 in response to movement of a coin through a coinchute 40.

However, the present invention is in no sense limited to coin actuateddevices, and the switch 44 of Fig. 3 may be any desired type of switchcontrolled in any desired manner.

The motor 38 is preferably of the constant speed type such as aclock'motor, and drives the worm ML: As shown in Fig. 1, the motor 38has a shaft 42 which is directly connected to the upper extension 22 ofthe worm 10. The direction of rotation of the shaft 42 is such as torotate the worm it in direction to move the worm wheel i2 upwardly andrestore it to its uppermost position in which the worm shaft [3reengages the plunger 35 of the switch 36 and opens the switch contacts35a to stop the motor 38.

A feature of the invention is the automatic winding of the spring 25 sothat it is constantly loaded to rotate the worm l i whenever theescapement mechanism is actuated by energization of the magnet 32.

To this end, one end of the spring 25 is connected to the worm l l andthe other end is connected to the worm Iii. Obviously since the wormsare parallel toeach other the spring 25 must be bent into U shape inorder to be connected to both the worms. It, is also desirable tosupport the. spring 25 and this may be done by the U-shaped wire support40 which extends through the spring 25 and extends into recesses 4!provided therefor in the lower ends of the extensions 22, 22 on theworms l9 and H respectively.

The support it fits loosely within the recesses M so that it does notinterfere with the free rotation of the worms. It is retained inposition by the inherent tension of the spring 25. As clearly shown. theends of the spring 25 may be coupled to the lower extensions 22 on theworms by extending the ends of the spring through dia metrical apertures53 provided for that purpose in the extensions 22, 22.

Of course the spring 25 must not drive the worm ill. Ordinarily this isprevented by the frictional resistance to rotation of the motor shaft 42when the motor 38 is of the conventional clock type containing aspeed-reducing gear train or transmission. If the friction of the motoris to be'moved downwardly a predetermined distance. In other words, theefiect of a series of impulses applied to the magnet 32 is stored up bythe movement of the worm wheel l2. For example, if ten impulses areapplied to the magnet 32, the worm wheel [2 will be moved downwardly tentimes as far as it would be moved in response to one impulse, and themotor 38 will have to run ten times as long to restore the worm wheel l2into its uppermost position in which it opens the switch 36. a

Although, for the purpose of explaining the invention, one specificembodiment thereof has been described in detail, various departures fromthe exact construction shown can be made without departing from theinvention which is to be limited only to the extent set forth in theappended claims.

. I claim:

l. A device of the type described comprising: a diiferen'tial mechanismincluding a driven memher having a normal position of rest and twoseparate driving members therefor, each driving member being capable ofdriving said driven member independently of the other member; normallywound spring means in driving relation with one of said driving membersforidriving the latter in direction to move. said driven member awayfrom said normal position; control means for permitting controlledmovement of said one driving member by said spring means; motor meansfor driving said other driving member in direction to move said drivenmember back to its normal position; means actuated by movement of saiddriven member out of normal position for causing said motor means todrive said other driving member and actuated by movement of said drivenmember into normal position for causing said motor means to ceasedriving said other driving member and means coupling said spring meansto said other driving member for rewinding the spring means duringreturn movement of said driven member by said motor means.

'2. A device as described in claim 1 in which said two driving membersare rotary members having parallel axes and said spring means comprisesa helical spring having a return bend therein whereby the ends arecoaxial with respect to said driving members, and means connecting eachend of said spring to its coaxially associated driving member.

3. A device as described in claim 1 in which said two driving membersare rotary members having parallel axes and said spring means comprisesa helical spring having a return bend therein whereby the ends arecoaxial with respect to said driving members, means connecting each endof said spring to. its coaxially associated driving member, and a Ushaped guide rod extending through said helical spring for supportin it.

4. A device as described in claim 1 in which said driven member consistsof a worm wheel and said driving members consist of a pair of parallelwormsmeshing with said wheel; a shaft supporting said worm wheel forfree rotation; and means supporting said shaft for linear movementthrough a path parallel to said arms.

5. A device for measuring predetermined increments of time comprising: amovable member having a normal position of rest;' normally wound springmeans for moving said member away from said normal position; controlmeans for permitting controlled substantially instantaneous movement ofsaid member by said spring means through predetermined increments ofdistance; motor means for returning said member to said normal positionat a constant speed; means actuated by movement of said member out ofsaid position of rest for causing said motor means to drive said memberand actuated by movement of said member into said position of REFERENCESCITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,770,775 Hall July 15, 19302,048,121 Holtz July 21, 1936 2,106,042 Stark Jan. 18, 1938 2,106,582

Wall Jan. 25, 1938

